gluBeginSurface function

Artikkel
03/09/2021

The gluBeginSurface and gluEndSurface functions delimit a Non-Uniform Rational B-Spline (NURBS) surface definition.

Syntax

void WINAPI gluBeginSurface(
   GLUnurbs *nobj
);

Parameters

nobj: The NURBS object (created with gluNewNurbsRenderer).

Return value

This function does not return a value.

Remarks

The gluBeginSurface and gluEndSurface functions mark the beginning and end of NURBS surface definitions, which are defined with calls to gluNurbsSurface.

Call gluBeginSurface to mark the beginning of a NURBS surface definition.
Make one or more calls to gluNurbsSurface to define the attributes of the surface.

Exactly one of these calls to gluNurbsSurface must have a surface type of GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4.
To mark the end of the NURBS surface definition, call gluEndSurface.

The gluBeginTrim, gluPwlCurve, gluNurbsCurve, and gluEndTrim functions support trimming of NURBS surfaces.

Use OpenGL evaluators to render the NURBS surface as a set of polygons. Preserve the evaluator state during rendering with glPushAttrib(GL_EVAL_BIT) and glPopAttrib.

Examples

The following functions render a textured NURBS surface with normals; the texture coordinates and normals are also described as NURBS surfaces:

gluBeginSurface(nobj); 
    gluNurbsSurface(nobj, . . ., GL_MAP2_TEXTURE_COORD_2); 
    gluNurbsSurface(nobj, . . ., GL_MAP2_NORMAL); 
    gluNurbsSurface(nobj, . . ., GL_MAP2_VERTEX_4); 
gluEndSurface(nobj);

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Glu.h
Library	Glu32.lib
DLL	Glu32.dll

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